One day in 1966, the two-way radio in the corner of the medical clinic crackled: “Can you come see if there is a smallpox case in the village?”

William “Bill” Foege, M.D., MPH, jumped into his VW bug and bumped over the dirt plains of eastern Nigeria where he was serving as a medical missionary until he got to the village. Sure enough, it was smallpox.

At the time, public health experts thought the best way to rid the world of this ancient, often-lethal scourge was to vaccinate everybody. But Foege (pronounced “Fay-ghee”) didn’t have enough vaccine for everyone in the village.

As a consultant for the smallpox eradication program operated by the U.S. Communicable Disease Center (now the Centers for Disease Control and Prevention), he also knew blanket vaccination wasn’t foolproof. Sometimes public health workers only went to certain locations like schools to give shots. Sometimes they vaccinated the same students over and over again.

Was there another way?

Foege imagined himself as a smallpox virus. To jump from one person to another generally required close, prolonged contact. But what if the close contacts had already been vaccinated? Could the virus be stopped?

Perhaps, but first he had to find everyone suffering from smallpox.

So Foege, the lanky, gregarious son of a Lutheran minister, called local missionaries via two-way radio (there was no telephone service), and asked them to recruit a network of “runners” to canvas the villages in their areas.

The runners carried photographs showing the small and rubbery smallpox lesions. They asked children too young to do answer anything but the truth, “Have you seen anybody who looks like this?” Small boys and girls proudly pointed to the homes where smallpox sufferers lived.

Foege and his team then moved in to vaccinate their contacts—a technique now known as surveillance and containment or circle vaccination—and village by village, smallpox began to disappear.

“He was charming. He was persistent. He was intelligent. He was analytical,” says long-time friend and colleague William Schaffner, M.D., chair of Preventive Medicine at Vanderbilt University Medical Center. “And so he created this new approach—the find-and-contain through ring immunization, interrupting the chain of transmission strategy of smallpox eradication.